One factor for growing hairs is a certain kind of protein called “Keratin”, which is supplied from hair papillae and sebum vessels in the pores of the skin.
Laser depilation is effected by throwing a laser beam onto a selected spot on the skin, thereby causing denaturation of protein to prevent the supply of Keratin with the result that hair growth is prevented.
When the intense beam of light is thrown from the laser onto a selected area of the skin, a Joule heat will be generated to cause a variety of opto-thermo reactions, depending on the raised temperature of the organism at the selected area, as for instance the following may occur: carbonization is caused at 400 or higher degrees C.; vaporization at 100 or higher degrees C.; blood coagulation at 68 or higher degrees C.; and activation at 40 or lower degrees C.
A temperature rise of the organism above 42 degrees C. will cause denaturation of protein, thereby causing cells to die. If the number of dead cells should increase beyond a certain limit, the organism cannot return to its original state.
In effecting a required depilation treatment safely and effectively, therefore, it is necessary that the strength of the laser beam is so controlled that the temperature of the organism may not rise significantly above 42 degrees C.
A laser device for medical use can produce a laser beam of light strong enough to effect a required depilation efficiently. Common people other than authorized medical experts are not permitted to use such a laser device for medical operations, which is very expensive, also.
For these reasons the medical treatment of depilation by using a medical laser is expensive, and still disadvantageously the depilation treatment is restricted by time.
Also, people are liable to feel less pleasing to the medical depilation, desiring that a required depilation be effected like an aesthetic treatment.
In the hope of meeting such a demand one object of the present invention is to provide a cosmetic apparatus for depilation using a semiconductor laser diode, which is capable of producing a beam of light at a controlled energy level, different from an intense beam of light produced by the medical laser, thereby permitting common people to handle the semiconductor laser diode in effecting a required depilation economically and safely.